Upscaling Anodic Synthesis of TiO2 Nanotubes Film as Potential Material for Photoelectrocatalytic Applications: Influence of Electrolyte Overheating and Aging on Nanotube Morphology and Stability

Background: Among Advanced oxidation processes, heterogeneous photocatalysis have a great interest, because it uses only light has a source of energy. One of the main limiting processes in photocatalysis is the high probability of electron-hole pair’s recombination in the volume or at the surface of the photocatalyst particles. TiO2 nanotubes grown by anodic synthesis are widely studied because of the large number of potential practical applications especially in photocatalytic or photoelectrochemical applications. However, the preparation of these electrodes at large scale is still challenging due to some technological obstacles such as the electrochemical cell design or the precise control of nanotubes morphology, especially regarding electrolyte ageing and overheating during the synthesis. Objective: This study examines the electrochemical synthesis of TiO2 nanotubes supported on large titanium electrodes. Methods and Results: By understanding heat dissipation phenomenon during the synthesis, an optimized electrochemical cell was designed to prepare 6x4 cm 2 anodes. Then we aimed to control precisely the length of the nanotubes independently of electrolyte ageing. Indeed, It was previously observed that the electrolyte composition evolves (ageing) during the nanotubes synthesis and hence leads to nonreproducible nanotubes morphologies under time-controlled potentiostatic anodization conditions. Conclusion and Perspectives: To overcome this issue, we developed a Coulometric approach that allows to synthesize, reusing the same electrolyte, several electrodes with a great precision and reproducibility on the length of the nanotubes (2,7 μm ± 160 nm) despite electrolyte ageing. Subsequently, these electrodes can be integrated in a photocatalytic or photoelectrocatalytic process in a real wastewater treatment sector would be very relevant.

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Recent advancements of g-C3N4-based magnetic photocatalysts towards the degradation of organic pollutants: a review

Nanotechnology ◽

10.1088/1361-6528/ac3614 ◽

2021 ◽

Author(s):

Suma Das ◽

Avijit Chowdhury

Keyword(s):

Conjugated Polymer ◽

Environmental Remediation ◽

Reaction Medium ◽

Heterogeneous Photocatalysis ◽

Working Mechanism ◽

Electron Hole ◽

Practical Applications ◽

Earth Abundant ◽

Enhance Efficiency ◽

Photocatalytic Applications

Abstract Heterogeneous photocatalysis premised on advanced oxidation processes (AOPs) has witnessed a broad application perspective, including water purification and environmental remediation. In particular, the graphitic carbon nitride (g-C3N4), an earth-abundant metal-free conjugated polymer, has acquired extensive application scope and interdisciplinary consideration owing to its outstanding structural and physicochemical properties. However, several issues such as the high recombination rate of the photo-generated electron-hole pairs (EHP), smaller specific surface area (SSA), and lower electrical conductivity curtail the catalytic efficacy of bulk g-C3N4. Another challenging task is separating the catalyst from the reaction medium, limiting their reusability and practical applications. Therefore, several methodologies are adopted strategically to tackle these issues. Attention is being paid, especially to the magnetic nanocomposites-based catalysts to enhance efficiency and proficient reusability property. This review summarizes the latest progress related to the design and development of magnetic g-C3N4-based nanocomposites (NCs) and their utilization in photocatalytic systems. The usefulness of the semiconductor heterojunctions on the catalytic activity, working mechanism, and degradation of pollutants are discussed in detail. The major challenges and prospects of using magnetic g-C3N4-based NCs for photocatalytic applications are highlighted in this report.

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Bullying, School Violence, and Climate in Evolving Contexts

10.1093/oso/9780190663049.001.0001 ◽

2018 ◽

Cited By ~ 4

Author(s):

Ron Avi Astor ◽

Rami Benbenisthty

Keyword(s):

School Violence ◽

School Safety ◽

Media Coverage ◽

Large Scale ◽

Ecological Model ◽

Empirical Studies ◽

Practical Applications ◽

Teacher Student ◽

Area Of Interest ◽

New Research

Since 2005, the bullying, school violence, and school safety literatures have expanded dramatically in content, disciplines, and empirical studies. However, with this massive expansion of research, there is also a surprising lack of theoretical and empirical direction to guide efforts on how to advance our basic science and practical applications of this growing scientific area of interest. Parallel to this surge in interest, cultural norms, media coverage, and policies to address school safety and bullying have evolved at a remarkably quick pace over the past 13 years. For example, behaviors and populations that just a decade ago were not included in the school violence, bullying, and school safety discourse are now accepted areas of inquiry. These include, for instance, cyberbullying, sexting, social media shaming, teacher–student and student–teacher bullying, sexual harassment and assault, homicide, and suicide. Populations in schools not previously explored, such as lesbian, gay, bisexual, transgender, and queer students and educators and military- and veteran-connected students, become the foci of new research, policies, and programs. As a result, all US states and most industrialized countries now have a complex quilt of new school safety and bullying legislation and policies. Large-scale research and intervention funding programs are often linked to these policies. This book suggests an empirically driven unifying model that brings together these previously distinct literatures. This book presents an ecological model of school violence, bullying, and safety in evolving contexts that integrates all we have learned in the 13 years, and suggests ways to move forward.

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Preparation and photocatalytic performance of metallic Nb0.9Ta0.1S2/2D-C3N4 composite

Oxford Open Materials Science ◽

10.1093/oxfmat/itab005 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Hanxiang Chen ◽

Jianjian Yi ◽

Zhao Mo ◽

Yanhua Song ◽

Wenshu Yang ◽

...

Keyword(s):

Separation Efficiency ◽

Low Cost ◽

Metal Sulfide ◽

Electron Hole ◽

Practical Applications ◽

Energy And Environment ◽

Photocatalytic Application ◽

Light Utilization ◽

Ternary Metal ◽

Key Issues

Abstract Photocatalysis technology has potential application in the field of energy and environment. How to expand visible light utilization and promote the separation efficiency of the carriers are the key issues for the high active photocatalysts preparation and future practical applications. In this work, a ternary metal sulfide Nb0.9Ta0.1S2 was prepared and used as an electron collector in the photocatalytic application. As a result, the generated electrons are quickly transferred to the surface of the composite to participate in the reaction. It was demonstrated that the photocatalytic activity of 2D-C3N4 was enhanced after the modification of Nb0.9Ta0.1S2. The Nb0.9Ta0.1S2/2D-C3N4 composite material was synthesized by solvothermal method. The composition of 5% Nb0.9Ta0.1S2/2D-C3N4 showed the highest H2 evolution rate of 1961.6 μmolg−1h−1, which was 6.6 times that of 2D-C3N4. The 15% Nb0.9Ta0.1S2/2D-C3N4 exhibited the best activity in Rhodamine B degradation rate of 97% in 2 h, which is 50% higher than that of 2D-C3N4. Nb0.9Ta0.1S2/2D-C3N4 can be used as electron trap to promote the effective separation of electron–hole pairs. This work provides benchmarks in exploring low-cost and efficient cocatalyst.

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A Review of Photoelectrocatalytic Reactors for Water and Wastewater Treatment

Water ◽

10.3390/w13091198 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1198

Author(s):

Stuart McMichael ◽

Pilar Fernández-Ibáñez ◽

John Anthony Byrne

Keyword(s):

Chemical Compounds ◽

Research Area ◽

Heterogeneous Photocatalysis ◽

Semiconducting Materials ◽

Electron Hole ◽

Water And Wastewater Treatment ◽

Aqueous Environments ◽

Different Types ◽

Water And Wastewater ◽

Electrical Bias

The photoexcitation of suitable semiconducting materials in aqueous environments can lead to the production of reactive oxygen species (ROS). ROS can inactivate microorganisms and degrade a range of chemical compounds. In the case of heterogeneous photocatalysis, semiconducting materials may suffer from fast recombination of electron–hole pairs and require post-treatment to separate the photocatalyst when a suspension system is used. To reduce recombination and improve the rate of degradation, an externally applied electrical bias can be used where the semiconducting material is immobilised onto an electrically conducive support and connected to a counter electrode. These electrochemically assisted photocatalytic systems have been termed “photoelectrocatalytic” (PEC). This review will explain the fundamental mechanism of PECs, photoelectrodes, the different types of PEC reactors reported in the literature, the (photo)electrodes used, the contaminants degraded, the key findings and prospects in the research area.

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Anodic synthesis of TiO2 nanotubes by step-up voltages

Journal of Composite Materials ◽

10.1177/00219983211023791 ◽

2021 ◽

pp. 002199832110237

Author(s):

V Sivaprakash ◽

R Narayanan

Keyword(s):

Corrosion Resistance ◽

Tio2 Nanotubes ◽

Biomedical Applications ◽

Phase Changes ◽

Electrochemical Anodization ◽

Corrosion Resistant ◽

Anodization Process ◽

Anodic Synthesis ◽

Input Potential

Fabrication of TiO2 nanotubes (NTs) has extensive application properties due to their high corrosion resistant and compatibility with biomedical applications, the synthesis of TiO2 nanotubes over titanium has drawn interest in various fields. The synthesis of TiO2 NTs using novel in-situ step-up voltage conditions in the electrochemical anodization process is recorded in this work. For manufacturing the NTs at 1 hour of anodization, the input potential of 30, 40 and 50 V was selected. With increasing step-up voltage during the anodization process, an improvement in the NTs was observed, favoring corrosion resistance properties. The surface of NTs enhances the structure of the ribs, raising the potential for feedback over time. XRD was used to analyze phase changes, and HR-SEM analyzed surface topography. Impedance tests found that longer NTs improved the corrosion resistance.

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2D Nanomaterials for Effective Energy Scavenging

Nano-Micro Letters ◽

10.1007/s40820-021-00603-9 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Md Al Mahadi Hasan ◽

Yuanhao Wang ◽

Chris R. Bowen ◽

Ya Yang

Keyword(s):

Large Scale ◽

Waste Heat ◽

Material Selection ◽

Power Supplies ◽

Small Scale ◽

Energy Scavenging ◽

Power Sources ◽

Practical Applications ◽

2D Nanomaterials ◽

Self Powered

AbstractThe development of a nation is deeply related to its energy consumption. 2D nanomaterials have become a spotlight for energy harvesting applications from the small-scale of low-power electronics to a large-scale for industry-level applications, such as self-powered sensor devices, environmental monitoring, and large-scale power generation. Scientists from around the world are working to utilize their engrossing properties to overcome the challenges in material selection and fabrication technologies for compact energy scavenging devices to replace batteries and traditional power sources. In this review, the variety of techniques for scavenging energies from sustainable sources such as solar, air, waste heat, and surrounding mechanical forces are discussed that exploit the fascinating properties of 2D nanomaterials. In addition, practical applications of these fabricated power generating devices and their performance as an alternative to conventional power supplies are discussed with the future pertinence to solve the energy problems in various fields and applications.

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Application of Novel Non-Thermal Physical Technologies to Degrade Mycotoxins

Journal of Fungi ◽

10.3390/jof7050395 ◽

2021 ◽

Vol 7 (5) ◽

pp. 395

Author(s):

Mohammad Yousefi ◽

Masoud Aman Mohammadi ◽

Maryam Zabihzadeh Khajavi ◽

Ali Ehsani ◽

Vladimír Scholtz

Keyword(s):

Electron Beam ◽

Food Systems ◽

Large Scale ◽

Plasma Electron ◽

Pulsed Light ◽

Beam Radiation ◽

Practical Applications ◽

Electron Beam Radiation ◽

Non Thermal Plasma ◽

Agriculture And Food

Mycotoxins cause adverse effects on human health. Therefore, it is of the utmost importance to confront them, particularly in agriculture and food systems. Non-thermal plasma, electron beam radiation, and pulsed light are possible novel non-thermal technologies offering promising results in degrading mycotoxins with potential for practical applications. In this paper, the available publications are reviewed—some of them report efficiency of more than 90%, sometimes almost 100%. The mechanisms of action, advantages, efficacy, limitations, and undesirable effects are reviewed and discussed. The first foretastes of plasma and electron beam application in the industry are in the developing stages, while pulsed light has not been employed in large-scale application yet.

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A Short Review on Recent Advances of Hydrogel-Based Adsorbents for Heavy Metal Ions

Metals ◽

10.3390/met11060864 ◽

2021 ◽

Vol 11 (6) ◽

pp. 864

Author(s):

Suguna Perumal ◽

Raji Atchudan ◽

Thomas Nesakumar Jebakumar Immanuel Edison ◽

Rajendran Suresh Babu ◽

Petchimuthu Karpagavinayagam ◽

...

Keyword(s):

Heavy Metal ◽

Metal Ions ◽

Heavy Metal Ions ◽

Large Scale ◽

Water Bodies ◽

Dimensional Structure ◽

High Porosity ◽

Adsorption Method ◽

Toxic Heavy Metal ◽

Practical Applications

The growth of industry fulfills our necessity and promotes economic development. However, pollutants from such industries pollute water bodies which pose a high risk for living organisms. Thus, researchers have been urged to develop an efficient method to remove toxic heavy metal ions from water bodies. The adsorption method shows promising results for the removal of heavy metal ions and is easy to operate on a large scale, thus can be applied to practical applications. Numerous adsorbents were developed and reported, among them hydrogels, which attract great attention because of the reusability, ease of preparation, and handling. Hydrogels are generally prepared by the cross-linking of polymers that result in a three-dimensional structure, showing high porosity and high functionality. They are hydrophilic in nature because of the functional groups, and are non-toxic. Thus, this review provides various methods of hydrogel adsorbents preparation and summarizes recent progress in the use of hydrogel adsorbents for the removal of heavy metal ions. Further, the mechanism involved in the removal of heavy metal ions is briefly discussed. The most recent studies about the adsorption method for the treatment of heavy metal ions contaminated water are presented.

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Predicting AC Optimal Power Flows: Combining Deep Learning and Lagrangian Dual Methods

Proceedings of the AAAI Conference on Artificial Intelligence ◽

10.1609/aaai.v34i01.5403 ◽

2020 ◽

Vol 34 (01) ◽

pp. 630-637 ◽

Cited By ~ 2

Author(s):

Ferdinando Fioretto ◽

Terrence W.K. Mak ◽

Pascal Van Hentenryck

Keyword(s):

Deep Learning ◽

Power Systems ◽

Power Flow ◽

Optimal Power Flow ◽

Large Scale ◽

Renewable Energy Sources ◽

Electrical Power ◽

Practical Applications ◽

Fundamental Building Block ◽

Optimal Power

The Optimal Power Flow (OPF) problem is a fundamental building block for the optimization of electrical power systems. It is nonlinear and nonconvex and computes the generator setpoints for power and voltage, given a set of load demands. It is often solved repeatedly under various conditions, either in real-time or in large-scale studies. This need is further exacerbated by the increasing stochasticity of power systems due to renewable energy sources in front and behind the meter. To address these challenges, this paper presents a deep learning approach to the OPF. The learning model exploits the information available in the similar states of the system (which is commonly available in practical applications), as well as a dual Lagrangian method to satisfy the physical and engineering constraints present in the OPF. The proposed model is evaluated on a large collection of realistic medium-sized power systems. The experimental results show that its predictions are highly accurate with average errors as low as 0.2%. Additionally, the proposed approach is shown to improve the accuracy of the widely adopted linear DC approximation by at least two orders of magnitude.

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